The field of the invention relates generally to current source rectifiers (CSRs), and more particularly, to methods and control systems for controlling active rectifiers in CSR systems.
CSRs are commonly used in a variety of applications, such as in uninterruptible power supplies (UPSs), telecommunication and data centers, electric motors, etc., because of their ability to operate the CSR at unity power factor with sinusoidal AC currents. At the same time, efficiency is a fundamental criterion that is considered during selection of a CSR system. Therefore, reduction of losses is an important factor for successful market adoption of current source conversion technology.
There are two desirable, but competing, parameters associated with CSRs: high efficiency and low current distortion. Reducing switching losses by using some known modulation sequences introduces undesirable side effects in terms of input current distortion. Other known solutions, for example, increasing input filter capacitance or increasing the switching frequency, are not of practical use and may compromise cost/footprint or performance.